This invention relates to muzzle loading firearms, and, more particularly, to a nipple for muzzle loading firearms which employ percussion locks to ignite a propellant charge.
The basic elements of a percussion lock have been known for many years and include a spring loaded hammer, a percussion cap, and a nipple communicating with the powder in the firing chamber of the firearm through a bolster. The percussion cap containing explosive fulminate is placed over the end of the nipple. To fire the gun, the spring loaded hammer is released and strikes the cap, crushing it and detonating the fulminate inside. The resulting "flame" from the fulminate is a combination of burning gases and particulate sparks under high pressure, and this flame is conducted through a passage in the nipple and bolster into the firing chamber in the firearm, to ignite the powder charge.
In addition to conducting a sufficient flame from the cap to the powder charge, it is desirable that nipples limit flow of flame and gases exiting the firearm after ignition of the powder charge. If the flow of gases exiting the firearm is of great enough intensity and force, it may blow the ignition hammer backwards. This occurrence is referred to as "blow-back", and is generally undesirable because of the danger it represents to the user and the shock force load it applies to the hammer and its spring mechanism which may cause premature degradation of the hammer and spring.
Conventional nipples are designed to conduct enough of the ignition flame and sparks to light the main powder charge, yet limit the amount of flame and gases escaping from the firearm after ignition to minimize the occurrence of "blow-back". The conventional nipple geometry has a drilled passage therethrough with a primary, relatively large diameter cylindrical chamber at the cap receiving end of the nipple and a shorter, relatively small diameter throat or constricted chamber adjacent the mounting end of the nipple. The junction of the two chambers represents a sudden constriction in the flow passage.
More recently, there has been proposed a nipple employing a passage having a large diameter cylindrical inlet section which in turn communicates with an intermediate conical section which communicates with a small diameter cylindrical throat section. The portion of the inlet and throat sections adjacent the nipple ends are untapered to reduce "blow-back" from the firearm and simplify nipple construction. This type of nipple is illustrated in Pawlak U.S. Pat. No. 4,186,506.
Although the Pawlak nipple offers many advantages over prior art devices, this nipple geometry still provides a relatively sharp constriction in the overall flow passage which tends to limit the amount of ignition flame conducted to the main powder charge. This, in turn, decreases the reliability of ignition of the main powder charge and may prolong the time required to light the main powder charge.
Accordingly, it is an object of the present invention to provide a novel nipple for a muzzle loading firearm which maximizes the amount of ignition gas and sparks conducted to the main powder charge to enhance the reliability of ignition of the main powder charge.
It is also an object to provide such a nipple which reduces the time required for the ignition flame to light the main powder charge.
Another object is to provide such a nipple which limits the amount of gases and flame escaping through the nipple from the firearm.
Still another object is to provide such a nipple which may be fabricated relatively easily and economically and which is long lasting.